Effect of cosolutes on the rheological and thermal properties of Tara gum aqueous solutions

The influence of the concentration (5-20 mg/mL) of different cosolutes (sucrose and NaCl) on the rheological and thermal properties of concentrated Tara gum (TG) solutions (1.5-2.5% w/v) was investigated. Furthermore, the structural properties of the TG, TG-sucrose and TG-NaCl solutions were studied. The TG, TG-sucrose and TG-NaCl solutions exhibited a pseudoplastic and typical viscoelastic behavior of an entangled network structure. An increase in the TG concentration increased the pseudoplasticity and the elasticity of the solutions, while the incorporation of NaCl reduced these properties. Sucrose had little influence on the rheological properties of the TG solutions. The texture profile and the water holding capacity of the TG solutions were significantly influenced by the concentration of the TG and did not change with the addition of the cosolutes. The thermal stability of the TG solutions was reduced by NaCl and was not altered by sucrose. The microstructures of the TG solutions was significantly affected by NaCl, supporting the results obtained from rheological and thermal analyses. The results of this study may be useful for the formulation and processing of foods containing TG.